/**
 * Case where barycenter increases crossings after 1 iteration
 * b3 and b4 are swapped even though they make fewer crossings in their
 * original order.
 *
 * After one sweep, sorting both sides, the number of crossings is reduced to 1
 * (from 13 or 14).
 *
 * tree_100 is a larger example where the higher number of crossings is
 * maintained in subsequent iterations. 
 */

digraph increase
{
  a0 -> b0;
  a0 -> b1;
  a0 -> b2;
  a1 -> b3;
  a2 -> b3;
  a3 -> b4;
  a4 -> b0;
  a5 -> b1;
  a6 -> b2;
  a7 -> b3;
}

/*  [Last modified: 2008 12 30 at 21:48:59 GMT] */
